At production of wallboard, particle board and the like, the wood fibres and the wooden chips resp. are shaped under high pressure and elevated temperature in a press, in which a number of boards commonly are pressed at the same time. The loading of those multi platen presses is effected by means of a loading elevator, which is so designed that the entire package of transport plates, upon which the stampings are situated, are displaced by the pusher into the press. This consists of a number of pressing plates, which are displaceable vertically in relation to each other and which at loading of the press are opened so much that the transport plates can be well inserted between the pressing plates.
Hitherto it has been difficult to automatize the loading of the press, as the risk of breakdowns could not be excluded. The reason for breakdown can be e.g. that the loading elevator due to an incorrect level indication has a wrong level relative to the levels of the press, thus that when the transport plates are pushed in, one or more of them will not find an opening between the pressing plates and become deformed, both at contact against the press and against the pusher. Such a breakdown means a stoppage of several hours. Another reason causing breakdown is that one or more transport plates has any type of deformity, thus that the plate, when pushed in, will catch and is cocked, which if it happens outside the press also can influence adjacent transport plates in the elevator. If the breakdown takes place inside the press it is possible that the pressing plates are damaged. Another reason can be that the sieve on the transport plate comes loose from the transport plate and at the insertion is rolled up together with the stamping, whereby one or more heating plates are deformed.
Also at the extraction of the transport plates from the press by means of the extractor to the unloading elevator it is possible that breakdowns may occur. The pulling member at the transport plate can e.g. be deformed thus that the extractor will not seize it whereby the transport plate will remain in the press. It may also occur that the transport plate certainly is withdrawn from the press at the unloading, but that the stamping has got stuck on the underside of the press plate and will not follow the transport plate out of the press.